The overall goals of the project are: 1) to characterize Beta2-microglobulin (Beta 2m) on the surface of lymphocytes and specifically, 2) to characterize its relationship to other membrane components, especially those related to the histocompatibility system, 3) to define the Beta 2m system in mice, and 4) to investigate the possibility that either Beta 2m histocompatibility complex acts as a receptor for antigen on T cells or whether other macromolecules structurally related to these histocompatibility antigens, in association with Beta 2m may have this function. The goals set for the current year are: 1) to further define and characterize the Beta 2m antiserum in the mouse, 2) to evaluate the effect of antiserum to Beta 2m on T lymphocyte functions, and 3) to characterize Beta 2m on the surface of T and B lymphocytes. BIBLIOGRAPHIC REFERENCES: Armerding, D., R. T. Kubo, H. M. Grey, and D. H. Katz. "Activation of T and B lymphocytes in vitro: Presence of Beta2-microglobulin determinants on allogeneic effect factor". Proc. Natl. Acad., USA. Kubo, R.T., S.M. Colon, R.T. McCalmon, and H.M. Grey. "Some biological properties of Beta2-microglobulin and its antibody. Fed. Proc. April, 1976.